Plain English Meaning

RAs are cockpit warnings that don't just point out nearby traffic — they tell the pilot exactly what to do, vertically, to avoid a collision. They're the system saying 'climb now' or 'descend now,' not just 'watch out.'

Full Definition

Resolution Advisories are alerts issued by an airborne collision avoidance system (such as TCAS II) that direct the pilot to take a specific vertical maneuver — climb, descend, or maintain vertical speed — to resolve a predicted conflict with another aircraft. RAs are the second and more urgent stage of TCAS alerting, following Traffic Advisories (), and are issued when the system calculates that a collision requires immediate action.